A final campaign to bring the last Nazis to justice begins in Germany next week despite the advanced age of war criminals who have lain low for nearly 70 years.

Posters will be displayed in 2,000 locations in cities across Germany on Tuesday showing the entrance to the Auschwitz concentration camp, under the slogan, “It is late, but not too late”. A reward of €25,000 is on offer.

The conviction in Munich in 2011 of John Demjanjuk, a guard at the Sobibor camp, for complicity in mass murder set a precedent for bringing rank-and-file Nazi soldiers to justice after decades